There's always OMeta: http://www.cs.ucla.edu/~awarth/ometa/ http://www.cs.ucla.edu/~awarth/ometa/ This is a generalized tool that will let you specify any lang

There's always OMeta: http://www.cs.ucla.edu/~awarth/ometa/ http://www.cs.ucla.edu/~awarth/ometa/ This is a generalized tool that will let you specify any language you want and target Javascript. OMeta has been implemented in several different languages; the Javascript implementation is just a couple hundred lines of code.